This optical illusion has been confusing people for almost 500 years — can you figure it out?

"The Ambassadors" is an oil painting that was finished in 1533 by Hans Holbein the Younger.

If you look at the painting head-on, there's a giant shape towards the bottom that looks like a blob, for lack of a better word. But if you look at the painting from a different angle, the "blob" turns into a skull. It is painted from an "anamorphic perspective."

Art historians believe that the skull is a "memento mori" — a reminder of mortality. In Latin, "memento mori" translates to "remember you will die."